If AIDS education programs are to be optimally effective, they must be based on developmental research concerning what children and adolescents of different ages currently know and are capable of learning about AIDS, how they feel about it, and how cognitive and social-environmental factors contribute to their emerging understandings and attitudes. The descriptive surveys conducted to date generally have not tested developmental hypotheses, employed psychometrically sound scales, or attempted to identify influences on knowledge and attitudes. The current project is designed to test competing hypotheses about the development of AIDS understandings and attitudes derived from cognitive-developmental theory and a knowledge-base perspective on development emphasizing the importance of socialization experiences. Phase 1 will involve developing and administering psychometrically sound and developmentally appropriate measures of understandings of AIDS causality, symptomatology, and prevention and attitudes concerning AIDS. A cross-sectional developmental study of Hispanic and Anglo students in grades 2 to 12 wi11 be conducted, and the open-ended and structured interviews used in this study will also be administered to a special sample of children of low-income parents who have received treatment for drug use. Emphasis wi11 be placed on identifing the underlying bases for common misconceptions, examining how they change with age and affect attitudes, and exploring sociocultural variations in development. In Phase 2, a longitudinal, quasi-experimental study involving low- and middle-income Hispanic and Anglo students in grades 3, 6, and 9 will be conducted in order to: (1) evaluate the effectiveness of an experimental AIDS curriculum designed to correct commom misconceptions and teach principles of AIDS causality and prevention, and (2) assess the relative contributions of cognitive maturity, socialized knowledge, and sociocultural background to changes in AIDS understandings and attitudes.